Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:18.104.22.168.
Your query was changed from:
parsed.tbs_noct_fingerprint: 29989fdb8b4800437f966aebfcf5e8fbb8007c9dd44e09200adbcb1a14a6cb3f and precert: true
parsed.tbs_noct_fingerprint: 29989fdb8b4800437f966aebfcf5e8fbb8007c9dd44e09200adbcb1a14a6cb3f AND precert: true
If this isn't what you intended, you can run your raw query without expansion.